You probably have seen this apparatus before. But do you know what you're seeing? Let's have a look...
This is a Newton's cradle, also called a Newton's rocker or a ball clicker. It was so-named in 1967 by English actor Simon Prebble, in honor of his countryman and revolutionary physicist Isaac Newton.
Despite its seemingly simple design, the Newton's cradle and its swinging, clicking balls isn't just an ordinary desk toy. It is, in fact, an elegant demonstration of some of the most fundamental laws of physics and mechanics.
The toy illustrates the three main physics principles at work
Try pulling one ball away from the others and releasing it, the ball will swing and strike the second ball, which in turns sends the momentum through the series of balls causing the last ball to move away from the group. When the last ball swings back, its collision then causes the first ball to move away. This process repeats until it finally wears down. Pulling away several balls will result in the same number of balls moving away at the other end.
The physics toy and demo sold as "Newton's cradle" is also called "colliding balls", "Newton's spheres", "counting balls", "impact balls", "ball-chain", the "executive pacifier", and even, believe it or not, "Newton's balls." (Donald Simanek)
Here is an activity using the Newton's Cradle with students.
Check out more explanations and extensions!
Have cool science demonstrations you show your classes regularly? Save time and materials by making a quick video tutorial of your own for students. By using demonstrations and lab investigations regularly, students not only will know science, they can apply it!
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